http://foxg20old.acmesystems.it/doku.php?id=tutorial:1wire

Foxboard own system is now owfs
installation of owfs: make ended with some errors. Does not work. 
So will use the built in 1-wire. It is OK, just data format strange.

1-wire bus moved from PB16 (J7.5) to PB31 (J6.19)


cd /sys/bus/w1/devices
cd 28-000002c5a744 
cat 28-000002c5a744 


myfox:/sys/bus/w1/devices/28-000002c5a744# cat w1_slave
50 05 4b 46 7f ff 0c 10 1c : crc=1c YES
50 05 4b 46 7f ff 0c 10 1c t=85000

Always gives the default value of +85C. 
reducing R to 1k  or 1.5 k helps


Code to get out temperature, does not work under crontab, hex simbols screw up
--------------------------------------------------------
A=$(tail -1 /sys/bus/w1/devices/28-000002bb4cd2/w1_slave) 
echo $A
B=${A:29:30}
C=$(echo "scale=3; $B/1000" | bc)
echo $C
--------------------------------------------------------



Need to use python

wget http://foxg20.acmesystems.it/download/examples/scan1w.py
wget http://foxg20.acmesystems.it/download/examples/tread.py

chmod 777 *

cd /var/www/
./scan1w.py
./tread.py



Temperature out of python is often CRC error. Need to check if value OK. Via intermediate file. 

t1.py
----------------------------------------
#!/usr/bin/python
import time
import fox
indoor = fox.DS18B20("000002c5a744")
print "%.2f" % (indoor.getTemp())
----------------------------------------




t.sh
------------------------------------------
B=""
while (true);do
./t1.py > t1.txt
A=$(cat /var/www/t1.txt)
echo "A="$A
B=$(echo "scale=3; $A/1" | bc)
echo "B="$B
if [ -n "$B" ]; then
echo " sensor value good, breaking"; break
else echo " read sensor again"
fi
done
------------------------------------------